Curium(III) fluoride
Chemical compound
From Wikipedia, the free encyclopedia
Curium(III) fluoride or curium trifluoride is the chemical compound composed of curium and fluorine with the formula CmF3.[3] It is a white, nearly insoluble salt that has the same crystal structure as LaF3. It precipitates as a hydrate when fluoride ions are added to a weakly acidic Cm(III) solution; alternatively it can be synthesized by reacting hydrofluoric acid with Cm(OH)3. The anhydrous form is then obtained by desiccation or by treatment with hydrogen fluoride gas.[1]
 Crystal structure | |
| Names | |
|---|---|
| IUPAC name
Curium(III) fluoride | |
| Other names
Curium trifluoride | |
| Identifiers | |
3D model (JSmol) |
|
| ChemSpider | |
PubChem CID |
|
| |
| |
| Properties | |
| CmF3 | |
| Appearance | Colorless solid[1] |
| Melting point | 1406 ± 20 °C;[1] |
| ~10 mg/L | |
| Structure | |
| Rhombohedral, hR24 | |
| P3c1, No. 165[2] | |
a = 0.7012 nm, c = 0.7198 nm | |
Lattice volume (V) |
0.30650 |
Formula units (Z) |
6 |
| Thermochemistry | |
Std molar entropy (S⦵298) |
121 J/mol·K[1] |
Std enthalpy of formation (ΔfH⦵298) |
−1660 kJ/mol[1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
Preparation
Curium fluoride can be prepared by in the reaction of curium with fluorine ions in an aqueous solution under weakly acidic conditions:
- Cm3+ (aq) + 3 F− (aq) → CmF3 (s) ↓
Another possible preparation is the reaction of curium hydroxide with hydrofluoric acid, which also produces a hydrate of curium fluoride.[4]
